Abstract:
The National Oceanic and Atmospheric Administration (NOAA) has the statutory mandate to collect hydrographic data to support the compilation of nautical charts and for safe navigation and to provide basic data for engineering, scientific and other commercial and industrial activities. Hydrographic survey data consists primarily of water depths but also includes features (rocks, wrecks, etc.), ... navigation aids, shoreline and some bottom type information. Such data can also be used for storm surge modeling and fish habitat studies and support a variety of maritime functions such as port and harbor maintenance, coastal engineering, and coastal zone management. The primary data associated with all hydrographic surveys is water depth. Primary depth measurements are made with multibeam echosounder sonar or with a single beam echosounder if multibeam systems are not available. Multibeam technology obtains hundreds more sounding per unit time than single beam systems and covers a wide swath of the ocean floor. Side scan sonar is used to supplement single beam and multibeam soundings by searching the region between regular sounding lines to assist in detecting objects that project from the sea floor. Once completed hydrographic survey data can be accessed through the National Geophysical Data Center (NGDC): http://www.ngdc.noaa.gov/mgg/mggd.html

Purpose:
The primary purpose of high-resolution multibeam bathymetry is to support safe navigation. However, it can also be valuable to a variety of other users including the coastal stewardship community, geologists, mathematical modelers and habitat researchers.

DISTRIBUTION LIABILITY: These data are not for navigational purposes. While every effort will be made to ensure that these data are accurate and reliable, NOAA assumes no liability for any damage caused by any errors or omission in the data.